Governor Christie said Thursday that he expects the Federal Emergency Management Agency to update flood-elevation maps drafted after superstorm Sandy to make them less aggressive.

Appearing at a town hall-style event in Manasquan, Christie said he has been working with engineers at the state, county and municipal level to gather information to convince FEMA to make adjustments. The maps, which established a higher and significantly expanded flood plain, will govern rebuilding and will be used by insurance companies to set premiums.

Christie spoke a day after FEMA Administrator Craig Fugate told a U.S. Senate panel that the flood maps could be amended as residents navigate the rebuilding process. Christie went a step further, saying he knows the maps will be amended. The question, he added, is when.

“Every indication I’m getting from FEMA is that the next set of maps is going to be backed off fairly significantly from where they were before,” he said.

In December, FEMA released what it called “advisory” flood-plain maps for New Jersey's coastal areas that showed updated risks of flooding based on the agency’s most current data. The preliminary maps — which are not yet official, but were released earlier than planned to guide rebuilding — showed a significant expansion and rise in the flood plain.

Christie adopted those maps earlier this year, but he said Thursday that doesn’t mean he endorses them.

“I’ve adopted the maps as they are right now so that, for those who want to start to rebuild now, they know what the standards are and they know what the costs will be,” he said. “But that doesn’t mean that I agree with these maps, because I don’t.”

The maps are critical to Sandy victims who are rebuilding severely damaged homes because the new structures must be elevated at least one foot higher than the new advisory flood plain, which was elevated by several feet in most coastal areas. And elevating a home can add tens of thousands of dollars to the cost of rebuilding, construction experts have said. After the maps become official, they will determine who must pay flood insurance and help establish the premiums, which were already set to increase substantially before Sandy struck.

But many residents are holding off on rebuilding because they are unsure whether the maps will be revised before they become official, U.S. Sen. Tom Coburn said at a hearing in Washington on Wednesday. Fugate indicated that they will.

The footprint of the flood plain could shrink in some places, he said, but the projected flood elevations would not get higher.

“Probably the biggest change will be in some of the tidal backwater areas where it may reduce the vulnerability zone ... but the elevation requirements aren’t significantly changing,” he said.

Christie has proposed using the first wave of federal Sandy aid to give homeowners grants of up to $150,000 to rebuild or elevate their primary residences or make them more resistant to storms. The program and others are still awaiting approval from federal officials before the state begins taking applications.

The governor said Thursday that he expects the federal government to approve the state’s grant program in about two weeks.

Christie warned that people who do not elevate their homes according to the new maps could see their flood insurance premiums increase by as much as $30,000. But he said the advisory maps are aggressive and the state is working with its congressional delegation and local officials to make sure they are amended.

“We’ve been fighting with the freeholders in these counties, with the mayors in these counties, and their local engineers to bring all the evidence that we need to bring to bear to FEMA to make sure that they understand that these maps need to be changed,” he said. “I think we’re beginning to convince them, and I’m confident the maps are going to change. The only thing I’m not confident about is when.”